Radiation protection standards for the general population have constituted one of the most controversial subjects in the history of atomic energy uses. This paper reexamines the process in which the first such standards evolved in the early postwar period. While the existing literature has emphasized a "collusion" between the standard-setters and users, the paper seeks to examine the horizontal relationship among the standard-setters. It first examines a series of expert consultations between the United States and the United Kingdom. Representing a different configuration of power and interest, the two failed to agree on the assessment of genetic damage and cancer induction whose occurrence might have no threshold and therefore be dependent on the population size. This stalemate prevented the International Commission on Radiological Protection (ICRP), established in 1950, from formulating separate guidelines for the general public. Situations radically changed when the Bikini incident in 1954 led to the creation of more scientific panels. One such panel under the U.S. Academy of Sciences enabled the geneticists to bridge their internal divide, unanimously naming 100 mSv as the genetically permissible dose for the general population. Not to be outdone, ICRP publicized its own guidelines for the same purpose. The case examined in this paper shows that the standard-setting process is best understood as a series of "epistemic negotiations" among and within the standard-setters, whose agendas were determined from the outset but whose outcomes were not.
A star map with an elaborate appearance was discovered in 1998 on the ceiling inside the Kitora burial mound of Nara Prefecture (hereafter we call it the Kitora star map). From archaeological evidence, this ancient tumulus is considered to have been constructed between the end of the 7th century and the beginning of the 8th century. We had a chance to make anew positional measurements of the 28-xiu constellations depicted on this circular star map, with the purpose of inferring their observed time epoch. As sky positions of stars are subject to change due to the precession, we can estimate when the stars in the Kitora star map were observed. We adopted a statistical least-squares approach to minimize the mean positional shift for all the 28-xiu standard stars, where the positional shift of a star means the difference between its measured position and the one calculated using precession theory. For a confidence level of 90%, the confidence interval of the observation year for the Kitora star map was found to be [123BC, 39BC], or approximately 80BC ± 40. This obviously indicates that the star map is of Chinese origin. Thus, in order to investigate the relationship of the Kitora star map to ancient Chinese star catalogs, we made a statistical analysis of Shi-shi's Star Catalog, the oldest star catalog in China. By applying to it the same analysis technique as the one adopted for the Kitora star map, we obtained the confidence interval to be [65BC,43BC]. Comparison of this interval with that for the Kitora star map strongly suggests that the latter was drawn based on the Shi-shi's Catalog. A similar analysis of the Korean star map stone-inscribed in the 14th century, Ch'onsang Yolch'a Punyajido, also showed nearly the same time epoch. Finally we discuss the political and social background why the Kitora star map was produced in such an early time in Japan.
In 1960, Tihiro Ohkawa and D. W. Kerst at General Atomic (GA) proposed an inertial ring device (so-called multipole) program for plasma confinement. After Kerst left for the University of Wisconsin, Ohkawa and his group made a linear octopole device to show that injection from coaxial plasma gun was stable. Against GA theoretical group's opposition to launching the multipole program, Ohkawa's unit demonstrated that the multipole device could produce quiescent plasma. In 1965, Ohkawa reported the result of their study using the "Toroidal Octopole" at the Second International Conference on Plasma Physics and Controlled Nuclear Fusion Research. L. Spitzer called it "a major milestone of the controlled fusion programme" in his summary of the conference. Thereafter, Ohkawa's group started a comparative study between octopole and quadrupole systems. "Toroidal Octopole" was converted to "Toroidal Quadrupole" configuration to see whether the conversion affected the degree of instability. They consequently found that the plasma confinement of quadrupole was less stable than that of octopole due to a shallow magnetic well. Ohkawa thought that the purpose of the multipole program was to find its fundamental difficulty and to see if it could be removed. He came to the conclusion that multipole devices would not become a practical fusion reactor, and therefore proposed to change multipole internal rings into toroidal plasma current. The purpose of Ohkawa's experiment was the construction of "Holy Grail (stable state of confinement plasma)" for MHD (magneto-hydro-dynamics) instability. Consequently, Ohkawa's group on toroidal multipole research demonstrated that "Holy Grail" was available for the structure of average minimum B. In addition, plasma physics on micro-instability made progress on the basis of their experiments.